1. Field of the Invention
The present invention relates to devices used in ligament repair and replacement surgery for securing under tension a ligament end to a bone surface.
2. Prior Art
In the area of ligament repair and replacement surgery it has been common to utilize a staple arrangement to attach a ligament end to a bone surface. An example of such staple device and its use is shown in a patent to Shapiro, U.S. Pat. No. 4,414,967. The Shapiro patent illustrates an arrangement where, with tension applied to the ligament end and staple legs positioned to straddle the ligament, the staple legs are driven into the bone with the staple web sandwiching and binding the ligament against the bone.
Examples of other devices for connecting ligament ends to a bone surface or to within a bone are shown in a patent of the present inventors, U.S. Pat. No. 4,632,100, and in a U.S. patent application Ser. No. 015,432, as well as in a patent to one of the present inventors, E. Marlowe Goble, U.S. Pat. No. 4,738,255. Additionally, another example of a ligament anchor system is shown in a United States patent to Hunt, et al., U.S. Pat. No. 4,590,928.
The above cited ligament anchor devices and systems all provide for fixing a ligament to a bone surface or to within a bone during healing where the bone and ligament bond together. This is also the function performed by the channel ligament clamp of the present invention. The present invention, however, provides a superior pull out strength to such earlier devices, particularly staple-type arrangements.
The channel clamp of the present invention provides a number of pointed spikes and pins as well as at least one screw-type coupling. Which pins and screw-type couplings are passed through the ligament and into the bone with the spikes containing the ligament. This arrangement provides a number of points of rigid support through the ligament for clamping it securely to the bone surface. Heretofore, certain fixation devices that have been employed for holding a ligament end onto a bone surface have included a disk or plate to receive a screw therethrough for seating in the bone. Such devices have incorporated spikes that extend from a ligament engaging surface for penetrating to grip the ligament surface but do not pass through the ligament. So arranged, as the screw is turned into the bone, the ligament engaging surface sandwiches the ligament against the bone. Examples of such fixation devices are manufactured by Synthes Canada, Ltd., of Mississauga, Ontario, Canada. These fixation devices, however, by their arrangement of spikes for gripping the ligament surface, do not provide the coupling strength of the channel clamp of the present invention.